Created module idea-test-framework and moved classes needed for idea tests there

Moved tests for completion and their test data into module idea-completion

idea/idea-completion/testData/smart/whenEntry/2.kt

@@ -0,0 +1,16 @@
+enum class E {
+    A
+    B
+    C
+}
+
+fun foo(e: E) {
+    when(e) {
+        E.A, <caret>
+    }
+}
+
+// ABSENT: A
+// EXIST: { lookupString:"B", itemText:"E.B" }
+// EXIST: { lookupString:"C", itemText:"E.C" }
+// ABSENT: else